1. Field of the Invention
The present invention relates to slide cover mounting technology and more particularly, to a slide cover lifting structure for use in an electronic device, for example, tablet computer, in the transmission shaft which enables the top cover panel of the electronic device to be moved smoothly and stably in horizontal relative to the base panel of the electronic device and then lifted from a horizontal position to a tilted position is kept in the base member of the electronic device.
2. Description of the Related Art
There are tablet computers that comprise an operating system end arranged at the bottom side of a LCD display panel in such a manner that the LCD display panel can be moved horizontally relative to the operating system end and then lifted to a tilted position so that the user can use the keyboard on the operating system end. To satisfy this operation, a special slide cover mounting arrangement is necessary.
U.S. patent application Ser. No. 13/156,672, invented by the present inventor, discloses a slide cover mounting design entitled “DOUBLE SLIDING STABILITY SPACE-SAVING SLIDE COVER LIFTING STRUCTURE”. According to this design, two gears are mounted on an axle near its two distal ends and the two distal ends of the axle are respectively pivotally coupled between two sliding rail mechanisms so that the cover panel of the electronic device can be turned about the pivot shafts of the hinges relative to the base member, and at the same time, the gears are kept in mesh with the respective gear racks stabilizing movement of the cover panel relative to the base member.
According to this design, the axle and the gears are installed in the sliding rail mechanisms, i.e., at the side of the LCD screen of the cover panel. When the cover panel is changed from the close position to a sliding status and then opened to a 75° angle position, the fixed axle will be moved with the LCD screen of the cover panel and exposed to the outside. In order to maintain the sense of beauty, a protective covering must be added to the cover panel. In consequence, the base member must provide an accommodation space for accommodating the protective covering when it is closed on the base member. This accommodation chamber limits the utilization of the internal circuit board space of the base member, causing unfavorable effects on tablet computer fabrication.
Further, because the hinges that are provided at the cover panel to provide torque are kept apart at a long distance, they tend to spring back when the cover panel is lifted. In this prior art design, there is no any other support design, and therefore the size of the hinges must be relatively increased to avoid spring back, not in conformity with compacting design.
Further, in the aforesaid prior art design, spring plates are used for stopping against the respective sliding rails to stop the cover panel in the open or close position. However friction between the spring plates and the sliding rails will cause surface damage. An improvement in this regard is necessary.